Category Archives: Invasive Plants

Lesser Celandine or Fig Buttercup It’s the last day of April, 2015 and beautiful 9 petal bright yellow buttercup flowers cover lawns, hill sides, stream banks, bogs and anyplace ground cover can grow. Uprooting one of the multi-stem plants reveals the cluster of tubers that identify it as fig buttercup, also known as lesser celandine — a native European invasive to Long Island.

A website search discovered that this recent, fast growing plant is exploding in the Pacific Northwest and beginning to do so here in the Northeast. And as with many of our invasives this plant is edible. The tubers, pulled before and after the flowers bloom can be boiled, roasted, and hot pickled. As with harvesting young invasive garlic mustard leaves, don’t be concerned about exhausting the supply.

Tubers of the Fig Buttercup

To slow the rapid growth of fig buttercup, start removing the plants as soon as they can be identified. Hand pull plants before they set seed or form bulbils. The stems of the heart shaped, wavy edged leaves, which may be solid green or with deep plum blotches, can be easily grabbed at the ground, and gently yet firmly wiggled and slowly pulled to uproot the tubers. If the ground is compact use a hand weeder garden tool. Cook or solarize the tubers to destroy them.

Garlic Mustard The young sprouts of the first year’s growth remain relatively small throughout the growing season and don’t flower. In late April/early May of the second year the plant matures with small clusters of white flowers at the top of each stalk. Uproot and leave the small first year’s seedlings on site. Uproot and solarize all other stages, beginning with the flowering stage of this plant to prevent seedpods from developing and dispersing.

Flowering Garlic Mustard

These flowering stems will continue to grow and produce seedpods — even if the entire plant is uprooted and composted or left on the ground and not destroyed. But first, because garlic mustard is edible, you may want to pinch off and cook the first year’s growth or the tender stems several inches below the young flowers in the plant’s second year. Then uproot, solarize and dispose of the rest yard waste collection.

Sauteed Garlic Mustard with Parmesan

Collect a bag of the flowering stems with the tender leaves and even the seedpods for a delightfully pungent green vegetable side dish. Saute and prepare as for broccoli rabe. Garlic mustard also makes a tasty pesto.

Japanese Knotweed Seedlings

Japanese Knotweed This shrublike plant can grow to over 10 feet tall. The stems are smooth, stout and swollen at joints where the six inch leaves meet the stem. Leaves are oval to somewhat triangular and pointed at the tip. In mid summer, small white sprays of flowers are followed by small winged seeds.

Japanese knotweed seedlings are edible. According to Wildman Steve Brill, “You can eat Japanese knotweed shoots from mid-April to early May, before the plant gets tough and woody.”

Juvenile plants can be hand pulled and should be done routinely throughout the growing season. Use a pulaski axe to remove the larger plants, including all roots and rhizomes. Any portions of the root system not removed will potentially re-sprout. All plant parts and seeds should be bagged, solarized and disposed of prevent them from reestablishing.

Long Island is home to both native and non-native vines. For instance, while our native poison ivy is considered a noxious weed by many, it is only so for people who suffer from rashes after touching the leaf, vine or root. Animals don’t have the same reaction, and in fact the berries are a good food source for them. Poison ivy is listed here among the non-native invasive plants because it grows alongside the truly invasive plants such as oriental bittersweet, winter creeper, English ivy, Japanese wisteria, honeysuckle, porcelain berry, mile-a-minute, and kudzu, and could easily be touched or brushed against by someone attempting to remove one of these non-native species. Another native vine is wild grape. While the berries are a feast for birds, the vines can bring down limbs and eventually kill trees from their dense leaf cover over the canopy, shading sunlight from host trees. (The best season for severing vines from trees is winter when other plants, which could impede access, are dormant. Click Vine Removal for details.)

Most Long Island soils harbor viable seeds from their arrival via wind, birds, or mammals years to decades ago. Under the right circumstances — exposure to sunlight being one — these seeds (possibly noxious weeds or more ivy) will quickly germinate and grow.

So, soon after removing vine roots, cover the ground with mulch (a thick layer of leaves) or replace them with native, shade loving plants (plugs or seeds) such as white wood aster Eurybia divericata, and then mulch. This hardy, fast growing species is a beautiful shade loving weed suppressant. It self-seeds, blooms throughout September and is a source of nectar and pollen for native pollinators. Click Native Plants in Recent Posts:

Oriental Bittersweet

Oriental Bittersweet: The vine of this species can eventually grow large enough to aggressively entwine trees and other plants. The roots are bright orange; flowers small and greenish-yellow; and fruits are pea-sized capsules that change to bright yellow and split open when ripe, revealing a bright orange-red berry within.

Cut large vines at the ground and dig or pull out small roots. Click Vine Removal for details.

Winter Creeper

Winter Creeper: Also known as creeping euonymus, in winter this evergreen vine produces a four-lobed pale green pod-like berry, which splits open to reveal the fleshy-coated orange seeds, one seed in each lobe. It often grows along with English ivy and should be removed in the same manner.

English or Common Ivy: An infested tree will exhibit decline for several to many years before it dies; and the added weight of vines makes trees susceptible to blowing over during storms. Cut vines at the foot of the tree and pull them from the ground for at least 2 feet around the tree. Gathered vines can be piled up and flipped semi-monthly until they desiccate..

Japanese Wisteria: Beautiful lavender flowers distinguish this vine, and is the reason this exotic species was brought to our shores nearly two centuries ago.

Cut and pull the vines and roots from the ground to effectively remove this plant. The twined vines should also be cut from the the trunk. Because this is a difficult plant to control, all of the plant material should be removed and discarded, as even the cut vines can set roots and regrow.

Honeysuckle

Honeysuckle: Several non-native species of this plant include shrubs and vines; may produce red or black berries; and have yellow, pink or red tubular flowers. Common traits: hollow pith stems, opposite, oval leaves with smooth margins (leaf edges).

The roots grow laterally just below the surface of the ground. Pull out all parts of the root to effectively control the plant. Revisit site every few weeks during the growing season to remove new growth from any remaining roots or seeds.

Porcelain Berry

Porcelain Berry: Similar in appearance to wild grape–even with tendrils–except that the pith (center of the vine) of porcelain berry is solid white; mature bark does not peel; berry colors include white, yellow, lilac, turquoise, green and pink, eventually turning dark blue; and leaves are generally small with deep lobes.

Remove and dispose of the entire root (often many feet long) and berries. Check on regrowth semi-monthly and remove suckers and seedlings as they occur.

Mile-a-Minute

Mile-a-Minute: Leaves of these thread-like vines grow quickly to cover and obscure sunlight from shrubs and young trees, interrupting plant photosynthesis.

Because this weed is an annual the root will not generate new growth. However the seeds are prolific. Remove the barb-bearing vines (be sure to wear thick gloves and long sleeves) in early August, just prior to flowering; bag, and allow to cook in full sun. Revisit the site annually to check for new growth.

Kudzu

Kudzu, aka The Vine That Ate the South: KUDZU AND GIANT HOGWEED HOTLINE: Residents should take photographs of suspect kudzu or giant hogweed plants and email them to ghogweed@dec.ny.gov . You can also call 845-256-3111 to report.

Get expert help from NYSDEC by calling the hotline noted above before attempting to remove this invasive

Poison Ivy

Poison Ivy: Most people recognize the three leaves of poison ivy. If you need a reminder, google search the name with “images” to see hundreds of photos. This picture was taken of the vine in winter without leaves. Here you’ll see the root hairs that attach to the tree. If allergic to the leaves of poison ivy you’ll want to protect yourself from the vines as well.

Notice that the vine in this photo is starting to encircle the foot of the tree. Cut, remove and dispose of this portion, and extract as much of the root as possible. Keep in mind that poison ivy is native to Long Island, and unless it is creating a health risk leave it for wildlife to enjoy.

Many of the trees we see growing on Long Island are highly invasive and non-native — commonly Chinese exotics brought here over 200 years ago. Today, most Long Island soils harbor viable seeds dispersed from their descendants via wind, birds, or mammals years to decades ago. Under the right circumstances — often sun exposure when land is cleared — these seeds will germinate and grow to out-compete native species.

Long Island’s invasive trees include the ubiquitous tree-of-heaven, Japanese angelica, Norway maple, and sycamore maple, plus some newcomers such as glossy buckthorn and Callery pear. Tree Control will address removing small seedlings and saplings — defined as young trees four inches or less in diameter at breast height. Larger tree removal may require a town permit and some trees may need treatment before cutting to prevent roots from sending out numerous sprouts.

Soon after removing tree seedlings and saplings, cover the open ground with mulch (a thick layer of leaves) or replace them with native, shade loving plants (plugs or seeds) such as white wood aster Eurybia divericata, and then mulch. This hardy, fast growing species is a beautiful shade loving weed suppressant. It self-seeds, blooms throughout September and is a source of nectar and pollen for native pollinators. Click Native Plants in Recent Posts:

Tree of Heaven in Flower

Ailanthus altissima, tree-of-Heaven aka tree from hell, is very invasive. It is often confused in appearance with our native sumacs and black walnut. The trunk of tree-of-heaven is smooth (no ridges) and blotchy — resembling pig skin. However, the outstanding difference is the single “tooth” at the base on the otherwise smooth margin of the leaflets. Black walnut bark is deeply ridged and the leaflet margins are toothed.

The tree-of-heaven is dioecious — meaning trees are either male or female. Annually, the females can produce 300,000 or more wind dispersed seeds, which deposit on open ground and germinate by the hundreds or thousands in large patches for great distances downwind of the trees. The female can be recognized by the feathery-looking seed stems that remain at the crown of the tree through the fall, winter, and early spring after the seed pods (samaras) have dropped. Since the tree aggressively sprouts when cut, the trunk is often girdled to kill it a year or so prior to cutting down. Click Tree Control for ideas on removing seedlings/saplings.

Norway Maple

Acer platanoides or Norway maple is similar in appearance to sugar maple. The easiest way to identify this tree is to break the leaf at the node where it joins the stem (petiole). You’ll notice white sap at the break, whereas saps from other maples are clear. Also, the point tips on Norway maple leaves have fine “hairs”, while the tips on other maple leaves are rounded.

The shallow roots of this species allow for simple removal of young trees and seedlings. See Tree Control.